Mitigation Proximity Tool

Federal Proximity Factor Tool: Out of Basin Compensatory Mitigation for U.S. Army Corps of Engineers (USACE)

The USACE Federal Proximity Factor Tool calculates the number of mitigation credits needed when a project impacts areas outside a mitigation bank’s service area. Here’s a concise summary of how to use the tool:

Location Relative to HUCs

  • One 8-digit HUC away: Multiplier = 1.5
  • Each additional 8-digit HUC: Add 0.25

 

In-Kind vs. Out-of-Kind Replacement

  • In-kind: Multiplier = 0
  • Out-of-kind: Multiplier = 0.75

 

EPA Level IV Ecoregions

  • Same Ecoregion: Multiplier = 0
  • Different Ecoregion: Multiplier = 0.25

Calculate Total Proximity Factor

  • Sum all multipliers to get the total proximity factor.

 

Determine Required Credits

  • Multiply the total proximity factor by the Corps-required credits for the project.

The Proximity Factor Tool plays a crucial role in determining the compensatory mitigation required when federal mitigation credits are used outside their designated service area. This tool, exclusively applicable to federal credits, ensures that mitigation remains effective even when no local mitigation options are available. It is regulated by the U.S. Army Corps of Engineers (USACE) and follows a case-by-case approval process, providing a structured framework for projects needing to offset environmental impacts in areas where no local federal credits exist.

What is the Proximity Factor Tool?

The Proximity Factor Tool is designed to calculate compensatory mitigation credits for projects where impacts occur outside a mitigation bank’s service area. This tool is essential for federal projects that cannot find sufficient mitigation credits within their Hydrologic Unit Code (HUC) or designated basin.

The tool evaluates the proximity between the impact site and the compensation site to calculate the necessary credits based on federal guidelines, ensuring that environmental resources are properly restored, even when the impact area lies outside a bank’s defined service area.

Conditions for Using the Proximity Factor Tool

To ensure proper compliance and effective mitigation, specific conditions must be met before using the tool for federal credits. These conditions include:

  1. No Local Alternatives:Before utilizing out-of-basin credits, it must be demonstrated that no federal credits are available within the local HUC or basin. This ensures that out-of-service area credits are used only when necessary.
  2. Mitigation Banking Instrument (MBI) Language:The MBI must clearly allow for the use of mitigation credits outside the designated service area. This regulatory language ensures that using the credits complies with federal regulations and maintains ecological integrity.

Case-by-Case Approval Process:

Each use of the Proximity Factor Tool for out-of-service area mitigation credits requires case-by-case approval from the relevant federal regulatory agencies. The U.S. Army Corps of Engineers (USACE) is responsible for ensuring that mitigation projects meet all federal environmental requirements before credits are applied outside the service area. This ensures that every project remains compliant with the overarching goal of protecting the environment.

The Proximity Factor Tool calculates the number of federal mitigation credits needed when impacts occur outside the mitigation bank’s service area. This involves assessing various environmental factors, including the distance between the impact site and the bank, and applying multipliers based on federal regulations (33 CFR 332).

The tool evaluates:

  1. Location relative to HUCs
  2. In-kind vs. out-of-kind replacement
  3. EPA Level IV Ecoregions

General Considerations for Using the Proximity Factor Tool

  1. Compliance with 33 CFR 332 Regulations:The proximity tool aligns with federal guidelines, ensuring that each compensatory mitigation project adheres to established standards.
  2. Corps’ Environmental Evaluation:The USACE evaluates each project based on its environmental impact, applying the proximity factor to determine the most appropriate mitigation strategy.
  3. Long-Term Ecological Benefits:The proximity factor helps promote the use of high-quality mitigation banks, ensuring that even when impacts occur outside a service area, the restoration of wetlands and ecosystems remains effective.

Benefits of the Proximity Factor Tool

  1. Expanded Mitigation Options:The tool allows developers and agencies to utilize mitigation credits from federal banks outside their service area when no local options are available, expanding the reach of wetland restoration efforts.
  2. Regulatory Compliance:Projects remain in full compliance with federal environmental regulations, reducing the risk of delays and ensuring a smooth approval process.
  3. Ecological Advantages:High-quality mitigation banks, regardless of their proximity to the impact site, can be leveraged to provide effective environmental compensation, benefiting ecosystems on a broader scale

Resources for Finding Suitable Mitigation Banks

To identify federal mitigation banks that allow for the use of credits outside their service areas, you can refer to resources such as the Regulatory In-lieu Fee and Banking Information Tracking System (RIBITS). RIBITS is a comprehensive database that tracks mitigation banking information, including out-of-service area provisions.

For more detailed guidance, refer to the documentation on the Proximity Factor Tool available through USACE.

The following mitigation banks allow consideration for Outside of Service Area (OSA) use.

*Federal Mitigation Bank list updated 4/22/25 

Bayfield Mitigation Bank
Big Cypress Mitigation Bank
Blackwater Creek Mitigation Bank
Bluefield Ranch Mitigation Bank
Boarshead Mitigation Bank
Corkscrew Regional Mitigation Bank
East Central Florida Mitigation Bank
Fox Branch Mitigation Bank
FPL Everglades Phase II Mitigation Bank
Hillsborough River Mitigation Bank
Hilochee Mitigation Bank
Horse Creek Mitigation Bank
Horseshoe Creek Mitigation Bank
Lake Istokpoga Mitigation Bank
Lake Louisa Mitigation Bank
Lake Washington Mitigation Bank
Little Pine Island Mitigation Bank
Loxahatchee Mitigation Bank
Mangrove Pointe Mitigation Bank
Myakka Mitigation Bank
Nature Coast Mitigation Bank
Nokuse Plantation Mitigation Bank
Panther Island Mitigation Bank
Peace River Mitigation Bank
Peach Drive Mitigation Bank
Pensacola Bay Mitigation Bank
Pigeon Creek Mitigation Bank
San Pedro Bay Mitigation Bank
Shell Creek Mitigation Bank
Southport Ranch Mitigation Bank
St. Johns Mitigation Bank
St. Marks River Mitigation Bank
Tampa Bay Mitigation Bank

Final Thoughts

The Federal Proximity Factor Tool is an essential resource for federal mitigation banking projects that need to offset impacts outside their service area. By adhering to USACE guidelines, developers can ensure that environmental restoration efforts are both effective and compliant. Contact The Mitigation Banking Group for expert guidance on utilizing the tool and navigating federal regulations for your project.

For more detailed insights, visit our Proximity Factor Tool Blog or consult our team for personalized assistance.